Campbell CR200 - Troubleshooting

Section 15. Alternate Telecoms Resource Library
142
• 05 Force Single Coil
• 15 Force Multiple Coils
• 16 Force Multiple Registers
15.1.3.5 Reading Inverse Format Registers
Some Modbus devices require reverse byte order words (CDAB vs. ABCD).
This can be true for either floating point, or integer formats. While other
CRBasic dataloggers, such as the CR1000, can use the MoveBytes() instruction
to output reverse byte order words, the CR200(X) does not have that capability.
If reverse byte order words are required, either the master has to make an
adjustment, which is sometimes possible, or the CR200(X) needs to replaced
with a datalogger that supports the MoveBytes() instruction.
15.1.4 Troubleshooting
Test Modbus functions on the CR200(X) with third party Modbus software.
Further information is available at the following links:
• www.simplyModbus.ca/FAQ.htm (http://www.simplymodbus.ca/faq.htm)
• www.Mo
dbus.org/tech.php (http://www.modbus.org/tech.php)
• www.la
mmertbies.nl/comm/info/modbus.html
(http://www.lammertbies.nl/comm/info/modbus.html)